The QJulianCalendar class provides Julian calendar system implementation. More...

#include <qjuliancalendar_p.h>

Inheritance diagram for QJulianCalendar:

Collaboration diagram for QJulianCalendar:

Public Member Functions
QString	name () const override
	Returns the primary name of the calendar.
bool	isLeapYear (int year) const override
	Returns `true` if the specified year is a leap year for this calendar.
bool	dateToJulianDay (int year, int month, int day, qint64 *jd) const override
	Computes the Julian day number corresponding to the specified year, month, and day.
QCalendar::YearMonthDay	julianDayToDate (qint64 jd) const override
	Computes the year, month, and day in this calendar for the given Julian day number jd.
Public Member Functions inherited from QRomanCalendar
int	daysInMonth (int month, int year=QCalendar::Unspecified) const override
	Returns number of days in the month number month, in year year.
int	minimumDaysInMonth () const override
	Returns the minimum number of days in any valid month of any valid year.
bool	isLunar () const override
	Returns `true` if this calendar is a lunar calendar.
bool	isLuniSolar () const override
	Returns `true` if this calendar is a lunisolar calendar.
bool	isSolar () const override
	Returns `true` if this calendar is a solar calendar.
QString	monthName (const QLocale &locale, int month, int year, QLocale::FormatType format) const override
	Returns the name of the specified month in the given year for the chosen locale, using the given format to determine how complete the name is.
QString	standaloneMonthName (const QLocale &locale, int month, int year, QLocale::FormatType format) const override
	Returns the standalone name of the specified month in the chosen locale, using the specified format to determine how complete the name is.
Public Member Functions inherited from QCalendarBackend
	QCalendarBackend ()=default
virtual	~QCalendarBackend ()
	Destroys the calendar backend.
QStringList	names () const
	Returns list of names this backend was registered with.
QCalendar::System	calendarSystem () const
	The calendar system of this calendar.
QCalendar::SystemId	calendarId () const
virtual int	daysInYear (int year) const
	Returns the total number of days in the year number year.
virtual int	monthsInYear (int year) const
	Returns the total number of months in the year number year.
virtual bool	isDateValid (int year, int month, int day) const
	Returns `true` if the date specified by year, month, and day is valid for this calendar; otherwise returns `false`.
virtual bool	isProleptic () const
	Returns `true` if this calendar is a proleptic calendar.
virtual bool	hasYearZero () const
	Returns `true` if year number `0` is considered a valid year in this calendar.
virtual int	maximumDaysInMonth () const
	Returns the maximum number of days in a month for any year.
virtual int	maximumMonthsInYear () const
	Returns the maximum number of months possible in any year.
virtual int	dayOfWeek (qint64 jd) const
	Returns the day of the week for the given Julian Day Number jd.
virtual qint64	matchCenturyToWeekday (const QCalendar::YearMonthDay &parts, int dow) const
virtual QString	weekDayName (const QLocale &locale, int day, QLocale::FormatType format) const
	Returns the name of the specified day of the week in the chosen locale, using the specified format to determine how complete the name is.
virtual QString	standaloneWeekDayName (const QLocale &locale, int day, QLocale::FormatType format) const
	Returns the standalone name of the specified day of the week in the chosen locale, using the specified format to determine how complete the name is.
virtual QString	dateTimeToString (QStringView format, const QDateTime &datetime, QDate dateOnly, QTime timeOnly, const QLocale &locale) const
	Returns a string representing a given date, time or date-time.
bool	isGregorian () const
QCalendar::SystemId	registerCustomBackend (const QStringList &names)
	Register this backend as a custom backend.

Static Public Member Functions
static QStringList	nameList ()
Static Public Member Functions inherited from QCalendarBackend
static QStringList	availableCalendars ()
	Returns a list of names of the available calendar systems.

Additional Inherited Members
Protected Member Functions inherited from QRomanCalendar
const QCalendarLocale *	localeMonthIndexData () const override
const char16_t *	localeMonthData () const override

Detailed Description

The QJulianCalendar class provides Julian calendar system implementation.

Since: 5.14

\inmodule QtCore

The Julian calendar, proposed by Julius Caesar in 46 BC (708 AUC), was a reform of the Roman calendar. It took effect on 1 January 45 BC (AUC 709), by edict. It was the predominant calendar in the Roman world, most of Europe, and in European settlements in the Americas and elsewhere, until it was refined and gradually replaced by the Gregorian calendar, promulgated in 1582 by Pope Gregory XIII.

The Julian calendar gains against the mean tropical year at the rate of one day in 128 years. For the Gregorian calendar, the figure is one day in 3030 years. The difference in the average length of the year between Julian (365.25 days) and Gregorian (365.2425 days) is 0.002%.

Source: \l {https://en.wikipedia.org/wiki/Julian_calendar}{Wikipedia page on Julian Calendar}

Definition at line 22 of file qjuliancalendar_p.h.

Member Function Documentation

◆ dateToJulianDay()

bool QJulianCalendar::dateToJulianDay	(	int	year,
		int	month,
		int	day,
		qint64 *	jd ) const

overridevirtual

Computes the Julian day number corresponding to the specified year, month, and day.

Returns true and sets jd if there is such a date in this calendar; otherwise, returns false.

See also: QCalendar::partsFromDate(), julianDayToDate()

Implements QCalendarBackend.

Definition at line 64 of file qjuliancalendar.cpp.

◆ isLeapYear()

bool QJulianCalendar::isLeapYear ( int year ) const

overridevirtual

Returns true if the specified year is a leap year for this calendar.

See also: daysInYear(), isDateValid()

Implements QCalendarBackend.

Definition at line 51 of file qjuliancalendar.cpp.

◆ julianDayToDate()

QCalendar::YearMonthDay QJulianCalendar::julianDayToDate ( qint64 jd ) const

overridevirtual

Computes the year, month, and day in this calendar for the given Julian day number jd.

If the given day falls outside this calendar's scope (e.g. before the start-date of a non-proleptic calendar), the returned structure's isValid() is false; otherwise, its year, month, and day fields provide this calendar's description of the date.